Fragrances are used in many products to improve their acceptance by consumers. For example, most personal products such as moisturizers, cleansers, and even household products such as laundry detergents use fragrances to improve their consumer acceptability. There have also been many studies conducted which have speculated that aroma greatly influences human psychology and physiology, and the term "aromatherapy" has been used to describe the beneficial properties which can be achieved using fragrances. In U.S. Pat. No. 5,238,915, various aromatic compositions or perfumes are discussed in relation to aromatherapy. In the '915, the prolonged release of perfume is accomplished by a pH adjusting tablet to provide a variable release of the perfume.
Volatile materials which are inhaled are included in many medications for treating conditions such as congested sinuses and coughing. For example, menthol and camphor are recognized by the United States FDA as safe and effective for the treatment of these conditions.
Effervescent compositions are known. These compositions generally combine carbonate salts such as sodium carbonate and/or sodium bicarbonate with acidic materials such as citric, tartaric, or fumaric acid in a way that carbon dioxide is released when the product is placed in water. These products must be packaged in ways that prevent unintended contact with water so that premature reaction is avoided. Even contact with humidity in the air must be prevented during manufacture and storage as this could detrimentally effect the effervescent properties. These effervescent compositions have been used with compounds such as aspirin or acetaminophen to treat headaches and stomach upset, been added with bleach and surfactants to clean dentures such as in U.S. Pat. No. 5,384,062, and included with fragrance and moisturizers to provide bath salts.
Various compositions are known which have exothermic heats of solution. A number of these are listed in Lange's Handbook of Chemistry, 11th edition, in Table 9-6(P9-107). The greater the value of the heat of solution, the more heat is liberated per gram-mole of the substance. Thus, materials with higher heats of solution are able to raise the temperature of a given amount of water higher than compounds with lower heats of solution. In U.S. Pat. No. 4,818,518, a dentifrice composition is described which provides a warming sensation using an exothermic reaction.
However, there still exists in the art a need for compositions which enhance the ability to promote release of volatile materials when placed in water.